Onychomychosis, a fungal infection of the nail bed, is very common in the toes of humans and animals. The fungus becomes established and propagates under the nail, and typically deep at the root of the nail. The fungus causes breakdown and delamination of the nail, and is evidenced by a grainy appearance and discoloration of the nail. Untreated the infection can last for years, and can spread to adjacent toes.
No satisfactory treatment is known for fungal nail infection. Oral medications are available, but are expensive, require long treatment periods, involve possible toxicity, and are not reliable. The most common oral medication is Lamisil®. However, a regimen of Lamisil® costs $1,000 to $1,500, must be taken for about six months, and has an associated potential liver toxicity and other undesirable side effects. The success rate of Lamisil® is no better than about 80%, even at twice the normal length of treatment. For all these reasons physicians are reluctant to prescribe Lamisil® for what amounts to a minor (although objectionable) cosmetic condition.
Numerous topical treatments are available, including one requiring a prescription.
In most cases a yearlong treatment regimen requires application several times a day. Reliable clinical studies on the effectiveness of topical treatments are not available, but estimates of the success rates with topical treatments are less than 10%. This is thought to be true even when used as directed and for the full duration of one year, which is rarely done due to the long time involved and persistence required. They all suffer from low cure rates due to the fact that the antifungal agent applied rarely reaches all the fungus. No topical treatment currently available penetrates the nail well-enough to effectively deliver an anti-fungal agent to the sub-nail region where it is needed for effective treatment. Most of it evaporates off or is rubbed off long before it has a chance to penetrate. Addition of agents like DMSO or urea to improve penetration is only minimally effective.
The third method of treatment is surgical or chemical removal of the nail. Removal of the nail allows direct access to the site of the fungal infection. This is the most effective but least appealing to most people. There are also significant costs in addition to pain involved and the cure rate is about 80% at best.
A need therefore exists for a safe, effective and economical treatment of fungal nail infection.